U.S. patent application number 17/657001 was filed with the patent office on 2022-07-14 for devices and methods for measuring portal pressure.
The applicant listed for this patent is BOSTON SCIENTIFIC SCIMED, INC.. Invention is credited to Laura Elizabeth CHRISTAKIS, Peter L. DAYTON, George DUVAL, Sean P. FLEURY, Douglas MELANSON, Vanessa MONAHAN, Cory P. WRIGHT.
Application Number | 20220218215 17/657001 |
Document ID | / |
Family ID | 1000006226735 |
Filed Date | 2022-07-14 |
United States Patent
Application |
20220218215 |
Kind Code |
A1 |
MELANSON; Douglas ; et
al. |
July 14, 2022 |
DEVICES AND METHODS FOR MEASURING PORTAL PRESSURE
Abstract
A system for measuring a pressure in a vein includes a needle
sized and shaped to be inserted through a working channel of an
endoscope. The needle is extending longitudinally and including a
channel extending longitudinally therethrough. The system also
includes a pressure sensing device including a longitudinally
extending body sized and shaped to be slidably inserted through the
channel of the needle and a sensor mounted on a distal portion of
the body and connected to a proximal portion of the pressure
sensing device via a connection cable. The sensor is configured to
detect information corresponding to a pressure of a flow of blood
through a vein.
Inventors: |
MELANSON; Douglas; (Natick,
MA) ; DAYTON; Peter L.; (Brookline, MA) ;
CHRISTAKIS; Laura Elizabeth; (Framingham, MA) ;
FLEURY; Sean P.; (Princeton, MA) ; WRIGHT; Cory
P.; (Woodbury, MN) ; DUVAL; George; (Sudbury,
MA) ; MONAHAN; Vanessa; (Natick, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOSTON SCIENTIFIC SCIMED, INC. |
Maple Grove |
MN |
US |
|
|
Family ID: |
1000006226735 |
Appl. No.: |
17/657001 |
Filed: |
March 29, 2022 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16548047 |
Aug 22, 2019 |
|
|
|
17657001 |
|
|
|
|
62728528 |
Sep 7, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 5/02152 20130101;
A61B 5/0053 20130101; A61B 5/022 20130101; A61B 5/14503 20130101;
A61B 5/6852 20130101 |
International
Class: |
A61B 5/0215 20060101
A61B005/0215; A61B 5/145 20060101 A61B005/145; A61B 5/00 20060101
A61B005/00 |
Claims
1-35. (canceled)
36. A system for measuring a pressure in a vein, comprising: a
needle sized and shaped to be inserted through a working channel of
an endoscope, the needle extending longitudinally and including a
channel extending longitudinally therethrough; and a pressure
sensing device including a longitudinally extending body sized and
shaped to be slidably inserted through the channel of the needle
and a sensor mounted on a distal portion of the body and connected
to a proximal portion of the pressure sensing device via a
connection cable, the sensor configured to detect information
corresponding to a pressure of a flow of blood through a vein,
wherein the pressure sensing device is longitudinally movable
relative to the needle between an insertion configuration, in which
the sensor is covered via a portion of the needle, and a pressure
sensing configuration, in which a distal end of the body of the
pressure sensing device extends distally past a distal end of the
needle to expose the sensor to a flow of fluid within the vein and
wherein the distal end of the body includes fins configured to
engage an engaging feature of the needle to define a maximum
distance by which the body can be extended out of the distal end of
the needle in the pressure sensing configuration.
37. The system of claim 36, further comprising a stylet sized and
shaped to be inserted through the channel of the needle, the stylet
being longitudinally movable relative to the needle between an
insertion configuration and a piercing configuration.
38. The system of claim 36, wherein the sensor is mounted within a
recess extending laterally into the body of the pressure sensing
device along the distal portion thereof.
39. The system of claim 36, wherein the body of the pressure
sensing device includes a through hole extending laterally through
the distal portion of the body so that a distal face of the sensor
is exposed to a flow of fluid passing through the through hole.
40. The system of claim 36, wherein, in the pressure sensing
configuration, the distal end of the body is moved distally past
the distal end of the needle by a predetermined distance, the fins
engage a portion of the needle preventing the body from being drawn
proximally into the needle.
41. The system of claim 36, wherein the pressure sensor is attached
to the pressure sensing device via the connection cable so that
when the pressure sensing device is in the pressure sensing
configuration, the pressure sensor is moved distally past the
distal end of the body.
42. The system of claim 41, wherein the pressure sensor falls away
from a longitudinal axis of the pressure sensing device when in the
pressure sensing configuration.
43. The system of claim 36, wherein the fins are configured so
that, when the body is moved a predetermined distance distally past
the distal end of the needle, the fins move from a first
configuration, in which the fins are constrained toward an exterior
surface of the body to a second configuration in which the fins are
moved radially outward to engage a portion of the needle.
44. The system of claim 43, wherein, when in the pressure sensing
configuration, the distal end of the body is moved distally past
the distal end of the needle by the predetermined distance, the
fins engage a portion of the needle preventing the body from being
extended distally out of the needle beyond the predetermined
distance.
45. The system of claim 44, wherein the needle includes an engaging
feature configured to engage the fins when the fins are in the
second configuration, a position of the engaging feature being
selected to ensure that the body is not extended distally out of
the needle beyond the predetermined distance.
46. The system of claim 45, wherein the engaging feature is one of
a recess and a groove formed in the needle.
47. The system of claim 43, wherein the fins are movable from the
second configuration to the first configuration via a pull wire
connected to the fins.
48. The system of claim 43, wherein an interior of the needle is
configured to interact with the fins so that the fins are movable
from the second configuration to the first configuration as the
body is withdrawn proximally into the needle.
49. The system of claim 48, wherein an interior surface of the
needle includes an angled surface at a distal end thereof
configured to move the fins from the second configuration to the
first configuration as the body is withdrawn proximally into the
needle.
Description
PRIORITY CLAIM
[0001] The present application is a Continuation of U.S. patent
application Ser. No. 16/548,047 filed on Aug. 22, 2019, which
claims priority to U.S. Provisional Patent Application Ser. No.
62/728,528 filed Sep. 7, 2018; the disclosure of which is
incorporated herewith by reference.
BACKGROUND
[0002] Portal pressure is used to understand and manage
hypertension, for example, in patients with liver cirrhosis.
Currently, a measure for portal pressure is extrapolated by
calculating a patient's hepatic venous pressure gradient (HVPG). A
balloon catheter with sensing capabilities is used to measure a
free hepatic venous pressure and a wedged hepatic venous pressure.
The HVPG is calculated by taking a difference between the free and
wedged hepatic venous pressures. The procedure for placing the
balloon catheter, however, is an invasive trans-jugular approach,
which provides only an approximated value for the portal
pressure.
SUMMARY
[0003] The present embodiments are directed to a system for
measuring a pressure in a vein, comprising a needle sized and
shaped to be inserted through a working channel of an endoscope,
the needle extending longitudinally and including a channel
extending longitudinally therethrough, and a pressure sensing
device including a longitudinally extending body sized and shaped
to be slidably inserted through the channel of the needle and a
sensor mounted on a distal portion of the body and connected to a
proximal portion of the pressure sensing device via a connection
cable, the sensor configured to detect information corresponding to
a pressure of a flow of blood through a vein.
[0004] In an embodiment, the pressure sensing device may be
longitudinally movable relative to the needle between an insertion
configuration, in which the sensor is covered via a portion of the
needle, and a pressure sensing configuration, in which a distal end
of the body of the pressure sensing device extends distally past a
distal end of the needle to expose the sensor to a flow of fluid
within the vein.
[0005] In an embodiment, the distal end of the needle may include a
sharp tip for piercing a wall of the portal vein and the distal end
of the body of the pressure sensing device may include a blunted
end so that, in the insertion configuration, the distal end of the
body is positioned relative to the sharp tip of the needle to
prevent the sharp tip from damaging the working channel of the
endoscope.
[0006] In an embodiment, the pressure sensing device may be
proximally movable relative to the needle so that the sharp tip is
exposed to pierce a wall of the vein.
[0007] In an embodiment, the distal end of the body of the pressure
sensing device may include a sharp tip and the distal end of the
needle may be blunted so that, in the insertion configuration, the
sharp tip of the pressure sensing device is housed within the
channel of the needle, and, in the pressure sensing configuration,
the pressure sensing device is moved distally relative the needle,
exposing the sharp tip of the body to pierce a wall of the portal
vein.
[0008] In an embodiment, in the pressure sensing configuration, the
distal end of the body may be moved distally past the distal end of
the needle via a predetermined distance. The pressure sensing
device may include fins coupled to the body so that the fins are
movable between a first configuration, in which the fins are
constrained toward an exterior surface of the body in the insertion
configuration, and a second configuration, in which the fins are
moved radially outward to engage a portion of the needle in the
pressure sensing configuration.
[0009] In an embodiment, the system may further comprise a stylet
sized and shaped to be inserted through the channel of the needle,
the stylet being longitudinally movable relative to the needle
between an insertion configuration and a piercing
configuration.
[0010] In an embodiment, a distal end of the stylet may include a
sharp tip and a distal end of the needle may be blunted so that, in
the insertion configuration, the sharp tip of the stylet is housed
within the channel of the needle and, in the piercing
configuration, the sharp tip of the stylet is moved distally past
the distal end of the needle.
[0011] In an embodiment, a distal end of the needle may include a
sharp tip and a distal end of the stylet may be blunted so that, in
the insertion configuration, the distal end of the stylet is
positioned relative to the distal end of the needle to prevent the
sharp tip of the needle from damaging the working channel of the
endoscope and, in the piercing configuration, the stylet is drawn
proximally relative to the needle to expose the sharp tip of the
needle for piercing a wall of the vein.
[0012] In an embodiment, the sensor may be mounted within a recess
extending laterally into the body of the pressure sensing device
along the distal portion thereof.
[0013] In an embodiment, the body of the pressure sensing device
may include a through hole extending laterally through the distal
portion of the body so that a distal face of the sensor is exposed
to a flow of fluid passing through the through hole.
[0014] The present embodiments are also directed to a device for
measuring a pressure within a vein, comprising a body extending
longitudinally from a proximal end to a distal, the body sized and
shaped to be inserted through one of a working channel of an
endoscope and a channel of an endoscopic needle, and a sensor is
positioned on a distal portion of the body, the sensor connected to
a proximal portion of the device via a cable connection, the sensor
configured to detect information corresponding to a pressure of a
flow of blood through a vein.
[0015] In an embodiment, the device may further comprise a working
channel extending longitudinally through the body.
[0016] In an embodiment, the sensor may be movable relative to the
body between a first configuration, in which a portion of the
sensor occludes a distal opening of the working channel extending
through the body, and a second configuration, in which the sensor
is moved away from a central axis of the body so that a tool
inserted through the working channel of the body has a clear path
for insertion into the vein.
[0017] In an embodiment, the device may further comprise a
cauterizing needle knife slidably housed within the body for
creating a hole in a wall of the vein through which the body is
insertable to measure the pressure of the vein.
[0018] The present embodiments are also directed to a method for
measuring a pressure in a vein, comprising inserting a needle
through a working channel of an endoscope to a target area
proximate a vein and piercing a wall of the vein and inserting a
distal portion of a pressure sensing device into the vein to
measure a pressure thereof, the pressure sensing device including a
sensor mounted on the distal portion and connected to a proximal
portion of the device via a connection cable.
BRIEF DISCLOSURE
[0019] FIG. 1 shows a schematic view of a system according to an
exemplary embodiment of the present disclosure;
[0020] FIG. 2 shows a longitudinal side view of a distal portion of
a pressure sensing device of the system of FIG. 1;
[0021] FIG. 3 shows a longitudinal side view of a distal portion of
a pressure sensing device according to an alternate embodiment;
[0022] FIG. 4 shows a schematic view of a system according to
another exemplary embodiment of the present disclosure;
[0023] FIG. 5 shows a schematic view of a system according to yet
another exemplary embodiment of the present disclosure;
[0024] FIG. 6 shows a schematic view of a system according to
another exemplary embodiment of the present disclosure;
[0025] FIG. 7 shows a schematic view of the system of FIG. 6,
including a pressure sensing device according to an alternate
embodiment of the present disclosure
[0026] FIG. 8 shows a schematic view of the system of FIG. 6,
including a pressure sensing device according to yet another
alternate embodiment of the present disclosure;
[0027] FIG. 9 shows a longitudinal side view of a distal portion of
a system according to another exemplary embodiment of the present
disclosure, in a first configuration;
[0028] FIG. 10 shows a longitudinal side view of the distal portion
of the system of FIG. 9, in a second configuration;
[0029] FIG. 11 shows a longitudinal side view of the distal portion
of the system of FIG. 9, in a third configuration;
[0030] FIG. 12 shows a longitudinal side view of a distal portion a
system according to an alternate embodiment of the present
disclosure, in a first configuration;
[0031] FIG. 13 shows a longitudinal side view of the distal portion
of the system of FIG. 12, in a second configuration;
[0032] FIG. 14 shows a longitudinal side view of a distal portion
of a system according to yet another exemplary embodiment of the
present disclosure, in a first configuration;
[0033] FIG. 15 shows a longitudinal side view of a distal portion
of the system of FIG. 14, in a second configuration;
[0034] FIG. 16 shows a schematic view of a system according to
another exemplary embodiment of the present disclosure;
[0035] FIG. 17 shows a longitudinal side view of a pressure sensing
device of the present disclosure according to another exemplary
embodiment of the present disclosure;
[0036] FIG. 18 shows a cross-sectional view of the pressure sensing
device of FIG. 17;
[0037] FIG. 19 shows a longitudinal side view a pressure sensing
device according to an alternate embodiment;
[0038] FIG. 20 shows a cross-sectional view of the pressure sensing
device of FIG. 19;
[0039] FIG. 21 shows a schematic view of a system according to yet
another exemplary embodiment of the present disclosure;
[0040] FIG. 22 shows a longitudinal side view of a system according
to another exemplary embodiment of the present disclosure, in a
first configuration;
[0041] FIG. 23 shows a longitudinal side view of the system of FIG.
22, in a second configuration;
[0042] FIG. 24 shows an enlarged side view of a sensor of the
system of FIG. 22;
[0043] FIG. 25 shows an enlarged end view of the sensor of FIG.
24;
[0044] FIG. 26 shows a schematic view of a passive senor according
to an exemplary embodiment of the present disclosure; and
[0045] FIG. 27 shows a schematic view of a passive sensor according
to another exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
[0046] The present disclosure may be further understood with
reference to the following description and the appended drawings,
wherein like elements are referred to with the same reference
numerals. The present disclosure relates to systems and methods for
measuring a portal pressure and, in particular, describes insertion
of a pressure sensing device into the portal vein via a needle that
is guided to the portal vein under endoscopic ultrasound guidance.
The pressure sensing device is inserted directly into the portal
vein to measure the portal pressure. Thus, the present disclosure
provides a non-invasive system and method for providing an accurate
measurement of the portal pressure. Although the exemplary
embodiments specifically show and describe the pressure sensing
device as including a sensor for measuring a pressure within the
portal vein, the sensor may also measure additional information, in
addition to pressure. Thus, it will be understood by those of skill
in the art that the below-described systems and methods may also be
utilized for obtaining and measuring information other than portal
vein pressure. It should be noted that the terms "proximal" and
"distal," as used herein, are intended to refer to a direction
toward (proximal) and away from (distal) a user of the device.
[0047] As shown in FIG. 1, a system 100 for measuring a pressure
within a portal vein 10 according to an exemplary embodiment of the
present disclosure comprises a needle 102 along with a stylet 104
and a pressure sensing device 106, each of which are passable
through a channel 108 of the needle 102. FIG. 1 further shows steps
1-4 for gaining access into the portal vein 10 using the system
100. Initially, the needle 102, with the stylet 104 received within
the channel 108 to prevent tissue from entering the channel 108
during insertion, may be passed through a working channel of a
flexible endoscope to be positioned proximate a patient's portal
vein 10, as shown in step 1. Once the needle 102 has been placed in
a desired position proximate to the vein, the stylet 104 may be
removed therefrom, as shown in step 2, and a sharp distal tip 110
of the needle 102 may be advanced to puncture a wall 12 of the
portal vein 10 so that a distal opening of the needle 102 is
positioned within the vein 10, as shown in step 3. Upon gaining
access to the portal vein 10, the pressure sensing device 106 is
inserted through the channel 108 into the portal vein 10, as shown
in step 4, so that a pressure sensor 112 in a distal portion 114 of
the pressure sensing device 106 is exposed to the flow of blood
through the portal vein 10 to measure the pressure in the vein
10.
[0048] The needle 102 extends longitudinally from a proximal end
(not shown) to a distal end 116 and includes the channel 108
extending therethrough. The needle 102 is preferably flexible and
is sized and shaped to be inserted through a working channel of a
flexible endoscope and is particularly configured to be visible
under ultrasound guidance so that the needle 102 may be guided to
the desired position proximate the portal vein 10. The distal end
116 of the needle 102, in this embodiment, includes the sharp
distal tip 110 to facilitate puncturing of the portal vein 10.
[0049] The stylet 104 extends longitudinally from a proximal end
(not shown) to a distal end 118 and is sized and shaped to be
slidable within the channel 108 of the needle 102. The distal end
118 is blunted so that, in an insertion configuration, the stylet
104 is received within the channel of the needle 102 with the
blunted distal end 118 aligned with the distal end 116 of the
needle 102 or extending slightly distally beyond the distal end 116
of the needle 102 to minimize damage to non-targeted tissue as the
tip 110 of the needle 102 is moved to the target site adjacent to
the vein 10 (i.e., to prevent the needle 102 from inadvertently
piercing or damaging tissue surrounding the path along which the
needle is inserted to the target site and to prevent tissue from
collecting within the channel 108 during insertion of the needle
102 to the target site.
[0050] The pressure sensing device 106, in this embodiment,
includes a flexible body 120 and the pressure sensor 112 positioned
along a distal portion 114 thereof. Those skilled in the art will
understand that the body 120 preferably has a flexibility
sufficient to enable the body 120 to be passed through the working
channel of a flexible endoscope as the endoscope traverses a
tortuous path to the target site adjacent to the vein 10. The body
120 extends from a proximal end (not shown) to a distal end 122 and
is sized and shaped to be slidably inserted into the channel 108 of
the needle 102. The pressure sensor 112 may be connected to a
proximal end of the device 106 via, for example, a connection cable
124 or other data transmission medium extending proximally from the
pressure sensor 112 through and along a length of the body 120. The
pressure sensor 112 may be an optical sensor or an electrical
sensor. As would be understood by those skilled in the art, an
optical sensor may require fluid to flow thereacross, which may be
analyzed to calculate a corresponding pressure value while an
electrical sensor may simply require contact with the blood within
the vein to measure a blood pressure thereof. However, those
skilled in the art will understand that any sensor capable of
measuring the pressure within the vein 10 may be employed and that
the sensor may forward data to a data processing arrangement in any
known manner including, for example, wireless, optical fiber and
wired connections. The pressure sensor 112 may be housed within or
mounted along the body 120 in any of a number of configurations as
would be understood by those skilled in the art.
[0051] In one embodiment, as shown in FIG. 2, the distal portion
114 of the body 120 includes a recess 126 extending laterally
thereinto and in which the sensor 112 is positioned. Where the
sensor 112 is, for example, a diaphragm-based optical sensor, the
sensor 112 may include an angled diaphragm 113 to allow for
adequate flow thereacross. This configuration also permits adequate
fluid contact where the sensor 112 is an electrical sensor. In
another embodiment, as shown in FIG. 3, a distal portion 114' of a
body 120' of a pressure sensing device 106' includes a hole 126'
extending transversely therethrough so that fluid flows across a
distal face 113' of a sensor 112' housed within the distal portion
114' via the hole 126'. The sensor 112', in this embodiment, may
be, for example, an optical sensor with a distal-facing diaphragm.
This embodiment may be particularly suited for reducing/preventing
air bubbles from forming around the pressure sensor 112', which
could lead to skewed pressure readings. A positioning ring may be
housed within the distal portion 114' to secure the pressure sensor
112' therewithin so that the pressure sensor 112' does not come
into contact with any portion of the body 120' which might cause
damage thereto during insertion of the pressure sensing device 106'
through even tortuous paths of the patient body.
[0052] According to an exemplary technique using the system 100,
the needle 102, with the stylet 104 received therewithin in the
insertion configuration, is inserted through a working channel of
an endoscope to a target area proximate a portal vein 10. As would
be understood by those skilled in the art, the needle 102 may be
guided to the portal vein 10 under, for example, EUS guidance via,
for example, the stomach or duodenum. Once the needle 102 is in a
desired position proximate the portal vein 10, the stylet 104 may
be withdrawn from the channel of the needle 102 so that the sharp
distal end of the needle 102 is exposed and the needle 102 may be
moved distally to penetrate the portal vein 10. Upon gaining access
into the portal vein 10 via the needle 102, the pressure sensing
device may then be inserted through channel 108 of the needle 102
until the pressure sensor 112 extends distally beyond the distal
end 116 of the needle 102 within the interior of the portal vein
10. The pressure sensor 112 within the portal vein 10 then provides
a blood pressure measurement thereof. For example, as described
above, a flow of blood within the portal vein 10 along diaphragm of
the pressure sensor 112 or contact with fluid with the pressure
sensor 112 provides a reading for the pressure measurement. Once
the pressure measurement of the portal vein 10 has been obtained,
the needle 102 and the pressure sensing device 106 may be removed
from the patient body. If desired, the pressure sensing device may
optionally be removed from the needle 102 and the stylet 104 may be
reinserted to the insertion configuration as the needle 102 is
withdrawn proximally back into the endoscope for removal from the
body.
[0053] Although the system 100 is shown and described as including
the pressure sensing device 106 including the pressure sensor 112
along the distal portion 114 of the elongated body 120 thereof so
that the pressure sensing device 106 may be immediately removed
from the body upon obtaining a pressure measurement, according to
another exemplary embodiment, the system 100 may include a pressure
sensing device that is deployed within the portal vein 10 to
provide periodic monitoring of the portal pressure. In this
embodiment, as shown in FIG. 26, a pressure sensing device includes
a pressure sensor 112'', which may be pushed through the needle 102
and into the portal vein 10 via, for example, the stylet 104 or any
other delivery device. The pressure sensor 112'' may be a wireless
passive sensor including a resonant tank circuit of a parallel
inductor and capacitor. In one embodiment, as shown in FIG. 26, the
passive sensor may be formed in a 1 mm by 1 mm form using
micro-machined traces for two parallel inductors sandwiching an
insulating substrate. The parallel inductive traces can be used to
create a parallel plate capacitance for the sensor. The passive
sensor may be anchored within the portal vein 10 via, for example,
a nitinol anchor wire which may act as an inductor or a part of an
inductor of the resonant tank circuit sensor. In another
embodiment, as shown in FIG. 27, a capacitor may be micromachined
on a polymer substrate which is attached to a loop wire.
[0054] In one embodiment, the inductive wire or coil may be trace
engineered to be several 10s of nH's. In one particular example,
the inductance may be 47 nH. The capacitance should be as large as
possible to ensure a lower resonant frequency given the physical
constraints and, in one example, may have a minimal value of 1 pF.
In one embodiment, the polymer substrate, which acts as an
insulator, may be formed of a polymer that will give under pressure
while maintaining a relative permittivity of greater than 4.
According to one example, the polymer substrate may have a
thickness of 10 .mu.m. In one embodiment, a high Q (quality factor)
is desired and may be achieved by increasing the turns and
splitting the coil evenly from the top and bottom layers, keeping
the ratio of the L/C high. In one embodiment, a resonant frequency
should be low enough to allow coupling from outside of the body
(e.g., below 1 GHz) and keeping the form factor small enough so as
not to interfere with the blood flow. In one embodiment, the
resonant frequency may range from between 800 MHz to 1000 MHz.
[0055] According to one example, a polymer made of flexible
laminate may allow for a dielectric constant (e.g., 9 or 10) which
allows for a high Q and smaller dimensions of the passive resonant
circuit. A nitinol wire, which may be used to anchor the passive
sensor, may allow more flexibility of the anchor. Controlling a
length of the anchoring wire would allow for an inductor ranging in
value from between 33-47 nH so that a parallel plate capacitor
sensor on the end may be valued from between 0.8 pF to 1.2 pF in
the space constraints of a disc having a size of 1 mm or smaller to
resonate within a range of 800 MHz to 1000 MHz.
[0056] The passive sensor 112'' may be read, for example, by using
a near field communication device that can be tuned to the resonant
frequency of the passive circuit as it is deployed from the body.
The resonant frequency will shift according to the change in
pressure so that extrapolating the pressure is achieved from
tracking the change in pressure deployed in the system versus its
neutral state before being introduced into the system. In one
embodiment, a near field communication device may be utilized via a
smart phone. A device including a variation of a loop antenna
multiplexed from transmit to receive with a voltage controlled
oscillator and receiver will be attached to a smart phone and
controlled by an application run on the phone. The application will
detect peak output from the passive sensor and read the frequency
setting while at peak. There will be a linear correlation to
frequency and pressure when the passive sensor is fabricated. A
calibration of the baseline frequency and sensitivity will be
created during initial testing to be used in the application of the
smart phone. A reading may be taken off the body by placing the
smart phone near the target area until, for example, an optimal
signal strength is indicated on the phone. Periodic readings of the
frequency may be acquired to monitor changes in pressure.
[0057] As shown in FIG. 4, a system 200 according to another
exemplary embodiment of the present disclosure is substantially
similar to the system 100 described above, comprising a needle 202
and a pressure sensing device 206. The system 200, however, does
not require a stylet, as shown in steps 1-4 of FIG. 4, to gain
access to the interior of a portal vein 20. Rather, the pressure
sensing device 206, which includes a blunt distal end 222, is
received within a channel 208 of the needle 202 during insertion of
the needle 202 through a working channel of an endoscope to a
target area proximate a portal vein 20. Similarly to the stylet 104
of the system 100, the pressure sensing device 206 of this
embodiment is positioned within the channel 208 of the needle 202
so that the blunt distal end 222 of the pressure sensing device 206
prevents tissue from entering the channel 208 and/or prevents the
sharp tip 210 of the needle 202 from damaging the working channel
of the endoscope during insertion of the needle 202 therethrough
and also prevents harm to non-targeted tissue as the needle 202 is
extended distally from the endoscope.
[0058] The needle 202 and the pressure sensing device 206 are
substantially similar to the needle 102 and pressure sensing device
106 of the system 100. As described above, the pressure sensing
device 206 includes a blunt distal end 222 and prevents the sharp
distal tip 210 of the needle 202 from damaging the working channel
of the endoscope during insertion. Thus, in an insertion
configuration, the pressure sensing device 206 is positioned within
the needle 202 such that a position of the bunt distal end 222 is
aligned with or protrudes slightly distally beyond the sharp distal
tip 210 of the needle 202. Accordingly, in this embodiment, the
pressure sensor 212 must be positioned along a distal portion 214
of a longitudinal body 220 of the pressure sensing device 206 such
that, when the pressure sensing device 206 is in the insertion
configuration relative to the needle 202, the pressure sensor 212
is covered by a portion of the needle 202. In other words, where
the sharp distal tip 210 of the needle 202 is formed via a tapering
at a distal end 216 of the needle 202, the pressure sensor 212
should be sufficiently distanced from the distal end 222 of the
body 220 such that the pressure sensor 212 is fully covered by a
portion of the needle 202 regardless of a rotational orientation of
the pressure sensing device 206 within the needle 202.
[0059] The system 200 may be used in a manner substantially similar
to the system 100. The needle 202, however, is inserted to the
target area with the pressure sensing device 206 received
therewithin in the insertion configuration, as shown in step 1.
Once the needle 202 has reached the target area, the pressure
sensing device 206 may be drawn proximally with respect to the
needle 202 so that the sharp distal tip 210 of the needle 202 is
exposed, as shown in step 2. The needle 202 is then advanced
distally so that a wall 22 of the portal vein 20 is punctured via
the sharp distal tip 210 and the needle 202 extends into an
interior thereof, as shown in step 3. Upon gaining access to the
interior of the portal vein 20, the pressure sensing device 206 is
moved distally with respect to the needle 202 until the pressure
sensor 212 is extends distally past the distal end 216 of the
needle 202 to measure pressure within the portal vein 20, as shown
in step 4.
[0060] As shown in FIG. 5, a system 300 according to another
exemplary embodiment may be substantially similar to the system 100
described above, comprising a needle 302, a stylet 304 and a
pressure sensing device 306. FIG. 5 shows steps 1-5 for gaining
access into a portal vein 30 using the system 100. Similarly to the
system 100, the needle 302 may be inserted through a working
channel of an endoscope to a target area proximate a portal vein
30, with the stylet 304 received therein, in an insertion
configuration. In this embodiment, however, the portal vein 30 is
pierced via a sharp distal tip 318 of the stylet 304 rather than
via the needle 302.
[0061] The needle 302 may be substantially similar to the needle
102 described above. A distal end 316 of the needle 302, however,
does not need to include a sharp tip. The distal end 316 may, for
example, include a distal face that extends substantially
transverse to a longitudinal axis of the needle 302, as the needle
302 is not required for puncture the portal vein 30.
[0062] In this embodiment, the stylet 304 may be substantially
similar to the stylet 104 described above with regard to the system
100. The stylet 304, however, includes a sharp distal tip 318. The
sharp distal tip 318 may be formed in any of a number of
configurations. In one example, the sharp distal tip 318 may be
formed via a tapered distal-facing surface extending at a
non-perpendicular angle with respect to a longitudinal axis of the
stylet 304.
[0063] In the insertion configuration, the stylet 304 is received
within a channel 308 of the needle 302 so that the distal tip 318
is aligned with the distal end 316 of the needle 302 or slightly
proximal thereto, as shown in step 1. This prevents the sharp
distal tip 318 of the stylet 304 from damaging the working channel
of the endoscope while also preventing any inadvertent collection
of tissue therewithin. Once the needle 302 and stylet 304 have
reached the target are proximate the portal vein 30, however, the
needle 302 is drawn proximally relative to the stylet 304 so that
the sharp distal tip 318 of the stylet 304 is exposed in a piercing
configuration, as shown in step 2. The needle 302 and stylet 304,
in the piercing configuration, are moved distally until the sharp
distal tip 318 of the stylet 302 penetrates the portal vein 30, as
shown in step 3. After the stylet 304 has pierced the portal vein
30, the needle 302 is advanced distally over the stylet 304 to
enter the portal vein 30. After the distal end 316 of the needle
302 has been positioned as desired within the portal vein 30, the
stylet 304 may be removed, as shown in step 4 and, as shown in step
5, the pressure sensing device 306 may then be inserted through the
needle 302 until a pressure sensor 312 mounted and/or positioned
along a body 320 of the pressure sensing device 306 is exposed to
the fluid flowing through the portal vein 30 to generate a portal
pressure measurement.
[0064] As shown in FIG. 6, a system 400 may be substantially
similar to the systems 200, 300 described above. Similarly to the
system 200, the system 400 comprises a needle 402 and pressure
sensing device 406, which may be used to access the portal vein 40,
as shown in steps 1 and 2 of FIG. 6. Similarly to the system 200,
the system 400 does not require a separate stylet as the needle 402
is inserted through a working channel of an endoscope to a target
area proximate the portal vein 40 with the pressure sensing device
406 received therewithin in an insertion configuration. In this
embodiment, however, the portal vein 40 is pierced via a sharp
distal tip 422 of a pressure sensing device 406, rather than via a
distal end 416 of the needle 402. Thus, the needle 402 is
substantially similar to the needle 302, as described above with
respect to the system 300, which does not include a sharp distal
tip.
[0065] The pressure sensing device 406 may be substantially similar
to the pressure sensing devices 206 described above, comprising a
longitudinally extending body 420 and a pressure sensor 412
positioned along a distal portion 414 thereof. Rather than a
blunted distal end, however, a distal end 422 of the body 420
includes a sharp tip 428, which may be formed via a tapering of the
distal end 422. The sharp tip 428 may have any of a number of
configurations. In one example, the sharp tip 428 may be formed via
a tapered distal-facing surface which extends at a
non-perpendicular angle relative to a longitudinal axis of the body
420. In another example, as shown in FIG. 7, a distal end 422' of a
body 420' of a pressure sensing device 406' may be substantially
conically tapered to form a sharp tip 428'. In yet another example,
as shown in FIG. 8, a distal end 422'' of a body 420'' may include
blunted edges 430'' with the sharp tip 428'' extending distally
therefrom. The sharp tip 428'' may be substantially conically
shaped. In both of the examples shown in FIGS. 7 and 8, the sharp
tips 428', 428'' are substantially centered relative to a
longitudinal axis of the body 420', 420'', respectively. Since the
sharp tips 428', 428'' are centered, a likelihood of the sharp tips
428', 428'' damaging the working channel of the endoscope is
reduced so that, if so desired, the pressure sensing devices
including the sharp tips 428', 428'' may be inserted directly
through the working channel of an endoscope, without the use of the
needle 402, to gain access to the portal vein.
[0066] As shown in FIGS. 9-11, a system 500 according to yet
another exemplary embodiment of the present disclosure may be
substantially similar to the systems 200, 400 described above,
comprising a needle 502 and a pressure sensing device 506. The
needle 502 and the pressure sensing device 506, however, include
additional features which allow the needle 502 and the pressure
sensing device 506 to interface with one another so that, when
moved from an insertion configuration to a pressure sensing
configuration, a distal end 522 of the pressure sensing device 506
moves distally beyond a distal end 516 of the needle 502 by a
predetermined distance. It will be understood by those of skill in
the art that this feature may be useful for measuring the pressure
within a portal vein since the portal vein is quite small in
comparison to other veins. Thus, the predetermined distance between
the distal end 522 of the pressure sensing device 506 and the
distal end 516 of the needle 502 in the pressure sensing
configuration may be set so that, when the system is in the
pressure sensing configuration in an operative position (i.e., in
the portal vein), the distal end 522 of the pressure sensing device
506 does not contact and/or pierce a far wall of the portal vein
into which it has been inserted preventing damage to the portal
vein.
[0067] The needle 502 may be substantially similar to either of the
needles 202 or 402, including a channel 508 through which the
pressure sensing device 506 may be inserted. The pressure sensing
device 506 may be substantially similar to either of the pressure
sensing devices 206 or 406, including a body 520 with a pressure
sensor (not shown) positioned along a distal portion thereof. A
distal end of either the needle 502 or the body 520 may include a
sharp tip for piercing the portal vein and gaining access thereto.
To prevent the pressure sensing device 506 from moving beyond the
predetermined distance relative to the needle 502, the body 520
includes fins 532 movable between a constrained configuration, in
which the fins 532 are moved toward an exterior surface 534 of a
body 520 of the pressure sensing device 506, and a outwardly biased
configuration, in which the fins 532 are moved radially outward,
away from the exterior surface 534 of the body 520. When the fins
532 are in the constrained configuration, the pressure sensing
device 506 may be received within the channel 508 of the needle 502
so that the system 500 is in the insertion configuration. As the
pressure sensing device 506 is moved distally relative to the
needle 502 toward the pressure sensing configuration, the fins 532
revert to their outwardly biased configuration to engage a portion
of the needle 502, thereby preventing further distal movement of
the pressure sensing device 506 with respect to the needle 502.
[0068] The fins 532 may be constrained via an interior surface of
the channel 508 of the needle 502, when in the insertion
configuration. Upon moving the pressure sensing device 506 distally
with respect to the needle 502, the fins 532 are freed to revert to
their outwardly biased configuration to engage a distal portion of
the needle 502 (e.g., a recess or groove along a distal portion of
the interior surface of the channel 508), when in the pressure
sensing configuration. In this embodiment, movement of the fins 532
may be controlled via one or more pull wires 536 so that, if it is
desired to draw the pressure sensing device 506 back into the
needle 502 toward the insertion configuration, the pull wire 536
may be drawn proximally relative to the pressure sensing device 506
so that the fins 532 are moved toward the constrained
configuration, and the pressure sensing device 506 may be drawn
back into the channel 508.
[0069] According to another example, as shown in FIGS. 12-13, a
system 500' may be substantially similar to the system 500,
comprising a needle 502' and a pressure sensing device 506'
including features which interface so that a distal end 522' of the
pressure sensing device 506' is moved distally beyond a distal end
516' of a needle 502' via a predetermined distance, when in a
pressure sensing configuration. Similarly to the pressure sensing
device 506, a body 520' of the pressure sensing device 506'
includes fins 532' movable between a constrained configuration and
an outwardly biased configuration, in which the fins 532' engage a
corresponding portion of the needle 502' when in the pressure
sensing configuration. The fins 532' in the embodiment, however,
are not controllable via pull wires. Rather, the fins 532' are
connected to the body 520' and configured so that, when it is
desired to move the system 500' from the pressure sensing
configuration to the insertion configuration, moving the pressure
sensing device 506' proximally relative to the needle 502' causes
the fins 532' to be constrained toward the constrained
configuration so that the pressure sensing device 506' may be drawn
into a channel 508' of the needle 502'.
[0070] For example, a proximal end 538' of the fins 532' may be
connected to the body 520' so that a distal end 540' of the fins
532' are movable toward and away from an interior surface 534' of
the body 520' in the insertion and pressure sensing configurations,
respectively. The fins 532' may be configured to engage a
correspondingly sized and shaped groove 542' along a distal portion
of the channel 508' in the pressure sensing configuration. The
groove 542' may include, for example, an angled surface 544'
extending proximally therefrom so that, when the fins 532' are slid
proximally against the angled surface 544', the fins 532' are moved
toward the constrained configuration so that the pressure sensing
device 506' may be drawn proximally into the channel 508' of the
needle 502'.
[0071] As shown in FIGS. 14-15, a system 500'' may be substantially
similar to the systems 500, 500' described above, comprising a
needle 502'' and a pressure sensing device 506'' including a body
520'' with fins 532'' for allowing a distal end 522'' of the
pressure sensing device 506'' to move distally beyond a distal end
516'' of the needle 502'' via a predetermined distance. The fins
532'' in this embodiment, however, are not movable. Rather, the
system 500'' is configured so that a distal end 540'' of the fins
532'' abuts against a radially inwardly extending protrusion 542''
of a channel 508'' of the needle" preventing any further distal
motion of the pressure sensing device 506'' relative to the needle
502''. Thus, the radially inwardly extending protrusion 542'' of
the needle 502'' acts as a stop preventing movement of the fins
532'' of the pressure sensing device 506'' distally
therebeyond.
[0072] Although the systems 500 (along with systems 500' and 500'')
specifically show and describe fins 532 for controlling a distance
via which the distal end 522 of the body 520 of the pressure
sensing device 506 extends distally from the distal end 516 of the
needle 502, it will be understood by those of skill in the art that
the above-described systems may include in any of a variety of
other features for controlling the distance via which the distal
end 522 of the pressure sensor 506 extends beyond the distal end
516 of the needle. For example, a handle member of the system 500
may include features (e.g., a spring loaded slider, a slider with
twisting lock, button) which causes the distal end 522 of the
pressure sensing device 506 to protrude from the needle 502 via a
predetermined distance.
[0073] As shown in FIG. 16, a system 600 according to another
exemplary embodiment comprises a pressure sensing device 606 which,
similarly to the pressure sensing devices described above, includes
a longitudinally extending body 620 with a pressure sensor 612
positioned along a distal portion 614 thereof. The pressure sensing
device 606, however, further includes a retractable needle knife
646 longitudinally movably housed within the body 620 for cutting a
small hole through a wall 62 of the portal vein 60 to gain access
thereinto. Since the pressure sensing device 606 in this embodiment
includes the needle knife 646 for gaining access to the portal vein
60, a separate needle and/or stylet is not required.
[0074] The pressure sensing device 606 may include a lumen 650
extending longitudinally though the body 620, within which the
needle knife 646 is slidably received. The needle knife 646 may be
movable between an insertion configuration, in which a distal end
648 of the needle knife 646 does not extend distally beyond a
distal end 622 of the body 620 of the pressure sensing device 606,
to a cutting configuration, in which the needle knife 646 is moved
distally with respect to the body 620 so that the distal end 648 of
the needle knife 646 extends distally beyond the distal end 622 of
the body 620 to cut a small hole though the wall 62 of the portal
vein 60. In one embodiment, the distal end 648 of the needle knife
646 may be sharp enough to create a small hole through the vein,
through which the body 620 of the pressure sensing device 606 may
be inserted. In another embodiment, the needle knife 646 may
utilize hot cautery to create a small hole through the wall 62 of
the portal vein 60. The needle knife 646 may be able to create a
smaller hole in the wall 62 of the portal vein than one formed via
a conventional needle, which may be advantageous depending on the
level of disease the patient is experiencing.
[0075] FIG. 16 shows steps 1-4 for gaining access to a portal vein
60 using the pressure sensing device 606. The pressure sensing
device 606 may be inserted directly through a working channel of an
endoscope to a target area within a patient body, with the needle
knife 646 housed within the body 620, in the insertion
configuration. As shown in step 1, a distal end 622 of a body 620
of the pressure sensing device is positioned proximate a wall 62 of
a portal vein 60 in a target position. Once the pressure sensing
device 506 is in the target position, the needle knife 646 is moved
from the insertion configuration to the cutting configuration, as
shown in step 2. The distal end 648 of the needle knife 646 may
then be used to a form a small hole in the wall 62 of the portal
vein 60, through which the distal end 622 of the body 620 may
follow through, as shown in step 3. As shown in step 4, the body
620 is inserted through the small hole until the pressure sensor
612 is exposed to a flow of blood through the portal vein 60. Once
the portal vein 60 has been accessed by the body 620, the needle
knife 646 is retracted into the body toward the insertion
configuration to prevent damage to the portal vein 60 as the
pressure reading is being taken.
[0076] Although the pressure sensing device 600 is shown and
described as being inserted directing through the working channel
of the endoscope to gain access to the portal vein 60, it will be
understood by those of skill in the art that the pressure sensing
device 606 may also be utilized with a needle, substantially as
described above with respect to the systems 200, 400. Inserting the
pressure sensing device 606 with a needle may be particularly
useful where there is concern regarding accessing the portal vein
through the stomach or duodenum. The needle knife 646 may be used
to access the vein once the needle is in the liver, reducing
potential bleeding.
[0077] As shown in FIGS. 17-18, a pressure sensing device 706
according to another exemplary embodiment may be utilized in any of
the systems 100-500, as described above. The pressure sensing
device 706 may be substantially similar to the pressure sensing
devices 106-506 including a longitudinally extending body 720
including a pressure sensor 712 positioned along a distal portion
714 of the body 720 and connected to a proximal portion of the
pressure sensing device 706 via a connection cable 724 (e.g.,
electrical, optical fiber) extending proximally from the pressure
sensor 712 along a length of the body 720. The pressure sensing
device 706, however, further includes a working channel 752
extending through the body 720 so that other diagnostic and/or
therapeutic tools may be inserted through the working channel 752
into the portal vein. The working channel 752 may extend along an
axis substantially parallel to a central longitudinal axis of the
body 720.
[0078] The pressure sensor 712 may also be offset from the central
longitudinal axis of the body 720 so that the connection cable 724
extends substantially parallel to the central longitudinal axis of
the body 720. In one embodiment, the pressure sensor 712 may have a
distal-facing diaphragm 713 and/or reading surface such that the
pressure sensor is mounted within a distal end 722 of the body 720
so that the distal-facing diaphragm is substantially flush with the
distal end 722. The pressure sensing device 706 may be used in
substantially the same manner as described above with respect to
the systems 100-500 (e.g., inserted through a channel of a needle)
to gain access to portal vein and take a pressure measurement
thereof.
[0079] According to an alternate embodiment, as shown in FIGS.
19-20, a pressure sensing device 706' may be substantially similar
to the pressure sensing device 706, comprising a longitudinal body
720' including a pressure sensor 712' connected to a proximal end
of the device 706' via a connection cable 724' along with a working
channel 752' extending longitudinally through the body 720'. The
pressure sensor 712', however, may be mounted within a recess 726'
extending laterally through a distal portion 714' of the body 720',
similarly to the pressure sensor 112 shown and described with
respect to FIG. 2. Since the pressure sensor 712', in this
embodiment, is distanced from a distal end 722' of the body 720',
the distal end 722' may be blunt (as shown) or, alternatively, may
include a sharp tip for piercing the portal vein. Similarly to the
pressure sensing device 706, the pressure sensing device 706' may
be used in a manner substantially similar to the portal veins
106-506, as described above with respect to the systems
100-500.
[0080] As shown in FIG. 21, a system 800 may be substantially
similar to the systems (e.g., systems 200, 400) described above,
comprising a needle 802 and a pressure sensing device 806, which
may be substantially similar to the pressure sensing device 706.
FIG. 21 shows steps 1 and 2 for measuring a pressure within and/or
providing treatment to a portal vein in which the pressure sensing
device 806 is inserted. The needle 802 may be substantially similar
to the needles 202, 402, including a longitudinal channel 808
through which the pressure sensing device 806 may be slidably
received. The pressure sensing device 806 may be substantially
similar to the pressure sensing device 706 including a working
channel 852 extending through a longitudinally extending body 820
of the pressure sensing device 806 for the passage of another tool
860 such as, for example, a diagnostic and/or therapeutic tool. A
pressure sensor 812, however, is not fixed within or along the body
820. Rather, the pressure sensor 812 is movably housed within the
body 820 between a first configuration (step 1), in which the
pressure sensor 812 is received within a distal end 822 of the body
820, and a second configuration (step 2), in which the pressure
sensor 812 is moved distally out of the distal end 822 so that the
pressure sensor 812, which is connected to a proximal end of the
pressure sensor device via a connection cable 824, is moved
laterally away from the distal end 822 as it extends distally
thereoutof. Although the distal end 822 of the body 820 is shown as
including a sharp tip while a distal end 816 of the needle 802 is
shown as being blunted, it will be understood by those of skill in
the art that, as described earlier with respect to systems 200 and
400, either the needle 802 or the pressure sensing device 806 may
include the sharp tip for piercing the wall of the portal vein to
gain access thereinto.
[0081] In the first configuration, a portion of the pressure sensor
812 partially occludes a distal opening 854 of the working channel
852. In one embodiment, when it is desired to insert the additional
tool 860 through the working channel 852, a physician or other user
may control the movement of the pressure sensor 812 from the first
configuration to the second configuration via a mechanism coupled
to a handle portion of the pressure sensing device 806 such as, for
example, a pull wire or spring loaded mechanism connected to the
connecting cable 824. Alternatively, the pressure sensor 812 may
automatically move from the first configuration toward the second
configuration (and vice versa) via a mechanical switch or sensor
which extends along the working channel 852 so that, when the
additional tool 860 is moved distally through the working channel
852, the mechanical switch or sensor is triggered to move the
pressure sensor 812, via a distal movement of the connection cable
824 relative to the body 820, distally beyond the distal end 822,
toward the second configuration. In the second configuration, the
pressure sensor 812 is moved distally past the distal end 822 of
the body 820 to extend laterally relative to a longitudinal axis of
the pressure sensing device 806. In other words, as the pressure
sensor 812 is moved distally past the distal end 822, the
connection cable 824 bends so that the pressure sensor 812 falls
away from the longitudinal axis of the pressure sensing device 806
to provide a clear path for the additional tool 860 to enter the
portal vein. In one embodiment, the connection cable 824 may
include shape memory characteristics so that, the connection cable
824 bends toward a predetermined configuration, when the pressure
sensor 812 is pushed out of the body 820.
[0082] Upon removal of the additional tool 860 from the working
channel 852, the pressure sensor 812 may be manually drawn back
into the body 820 toward the first configuration or, alternatively,
may be drawn back into the body 820 automatically via a mechanical
switch or sensor that is triggered as the additional tool 860 is
moved proximally through the working channel 852.
[0083] As shown in FIGS. 22-25, a system 900 according to another
exemplary embodiment of the present disclosure may be substantially
similar to the system 800, comprising a needle 902 and a pressure
sensing device 906. As described above, a portal vein may be
pierced via one of the needle 902 and the pressure sensing device
906 so that a pressure of the portal vein may be measured via a
sensor 912 of the pressure sensing device 906, which is inserted
into the portal vein. The pressure sensing device 906 may be
substantially similar to the pressure sensing device 806, including
a body 920 having a working channel 952 extending longitudinally
therethrough to allow an additional tool 960 to be inserted
therethrough to access the portal vein. Similarly to the pressure
sensing device 806, in a first configuration, the pressure sensor
912 occludes a portion of a distal opening 954 of the working
channel 952 so that, the pressure sensor 912 must be moved toward a
second configuration to permits passage of the additional tool 960
through the working channel 952 and into the portal vein. Rather
than being moved distally past a distal end 922 of the body 920,
however, in the second configuration, the pressure sensor 912 is
moved into correspondingly sized, shaped and positioned cavity 956
formed along an interior surface of the body 920.
[0084] In particular, as shown in FIGS. 22-23, the pressure sensing
device 906 is comprised of the longitudinally extending body 920
through which the working channel 952 extends, substantially
parallel to a central longitudinal axis of the body 920. The
pressure sensor 912 is positioned at the distal end 922 of the body
920 and is connected to a proximal portion of the pressure sensing
device 906 via a connection cable 924 extending longitudinally
through the body 920. The connection cable 924 may also extend
substantially parallel to the central longitudinal axis of the body
920. The connection cable 924 and the pressure sensor 912 are in a
longitudinally fixed position with respect to the body 920.
However, the pressure sensor 912 is laterally movable with respect
to the central longitudinal axis of the body 920. Specifically, the
body 920 includes a cavity 956 that is sized and shaped to
correspond with the pressure sensor 912. The cavity 956 is axially
aligned with the pressure sensor 912 so that, when the pressure
sensor 912 is moved toward the second configuration, the pressure
sensor 912 drops into and/or is pushed into the cavity 956 to
provide a clear path via which the additional tool 960 may be
inserted into the portal vein via the working channel 952.
[0085] In one embodiment, the pressure sensor 912 may include a
housing or casing 958 that is movably connected to the connection
cable 924. The housing 958 may be slid laterally relative to the
connection cable 924 between the first configuration and the second
configuration. In particular, the housing 958 may include a slot or
track 959, as shown in FIG. 25, within which a distal end 925 of
the connection cable 924 may slid to permit movement of the
pressure sensor 912 between the first and second configuration, as
shown in FIG. 24. The distal end 925 may include an enlarged end
received within the track 959 to prevent the connection cable 924
from being inadvertently disconnected from housing 958.
[0086] In an embodiment, the pressure sensor 912 may be biased
toward the first configuration. When the additional tool 960 is
inserted distally through the working channel 952 of the body 920,
a distal end 962 of the additional tool 960 may be pushed against a
rounded edge of the housing 958, which pushes the pressure sensor
912 into the cavity 956 toward the second configuration so that the
additional tool 960 may be moved distally therepast into the portal
vein. Upon removal of the additional tool 960, the pressure sensor
912 may revert to its biased first configuration.
[0087] As discussed above with respect to the systems 100-900,
pressure sensing devices may be guided to the portal vein under EUS
guidance. In some cases, the portal sensing devices described above
may also include an additional sensor for enabling magnetically
driven tracking and/or mapping. This feature may be particularly
useful where the pressure measuring device 606 is used without
ultrasound, or for training purposes to spatially verify the
location of the wire in the anatomy during an EUS procedure.
Alternatively or in addition, a magnetically driven or fiber optic
3D shaping sensor could be added as an additional control to track
the sharp tip of the pressure sensing device, needle, or stylet
used to gain access to the portal vein during the procedure.
Information provided to the user (e.g., physician) may be used as
safety feedback to ensure that an opposite side of the vein (i.e.,
a far wall of the vein) is not inadvertently punctured.
[0088] It will be apparent to those skilled in the art that various
modifications may be made in the present disclosure, without
departing from the scope of the disclosure.
* * * * *